[gnolivos]

Interestingly I made this change in bimmercode and I could swear I tested and it had worked.
However today I am driving at highway speeds and it’s again 3pm off.
Are we sure this works?

Also I know there is a similar coding with the word digital in it:
BC_DIGITAL_V_KORRECTUR
Makes me wonder if this is the proper one to change?

Originally Posted by JSaid

If you use BimmerCode and open up instrument panel, you can change:

BC_V_KORREKTUR

To ohne korrektur.

All fixed, your Speedo now shows the correct speed

[seccsc]

Originally Posted by Transfer

As others have said this is common, but which wheel/tire package do you have? According to my GPS radar detector my M340i with staggered 19" PS4S is exactly on the mark. 75 mph = 75 mph.

My old '07 335i and this car are exactly the same, 80 mph = 75 MPH exactly. I also have the staggered PS4S's.

[gnolivos]

So i found out today that there are changes to be made in KOMBI 3002 WEG that will allow to adjust exact speedometer readings.
Problem is I don't see 3002 WEG entry in expert mode in bimmercode.

If anyone has ISTA etc you can try applying this detailed fix:

https://www.m5board.com/threads/corr...coding.430570/

[Wet Fish]

Originally Posted by JSaid

If you use BimmerCode and open up instrument panel, you can change:

BC_V_KORREKTUR

To ohne korrektur.

All fixed, your Speedo now shows the correct speed

In UK. Change this and it still under reads.

[VipinLJ]

Originally Posted by Wet Fish

In UK. Change this and it still under reads.

I haven't corrected it in my BMWs yet. I prefer it compared to my other cars where, in my Mercs, the speedometer actually under reads the speed by 2mph (speedo shows 100mph and actual speed is usually 102-103mph) and Audi/VW where speedo under reads by 1mph or is spot on (VW speedo shows 100mph and actual speed is 101mph but my Audis have been spot on).

[iifymbro]

my radar detector is GPS and is saying my speedo is 5mph higher then actual

I can handle 2 or 3mph but 5...

[gnolivos]

Re: speed adjustment.
No known fix yet with bimmercode even on expert mode. Maybe with ISTA it can be done. I posted a potential ISTA fix that worked with previous f30 platform but no one has tried it.

[GD1981]

yep, my dragy has it off by 2-3 mph

[JABCAT]

Found this thread after noticing my Speedo reads 3 mph high. Fwiw all my other vehicles read dead on, so this one reading high is really not something I want, or should have to deal with. Is this not something that can be recalibrated by the dealer?

*19" staggered M 791 wheels.

[Seaford]

I was zapped by a roadside officer this morning…I had Driver Assist engaged and was showing thirty, the roadside display of my speed said 28.

[j luke]

Its part of the premium German car experience. Its so well built that going 75 really feels like you're going 72.


But, seriously, its "normal" in that all our BMWs do this.

[JABCAT]

Originally Posted by j luke

But, seriously, its "normal" in that all our BMWs do this.

So whether or not owners accept this (stupid, imo) quirk as being normal, I'm assuming it should be able to be corrected by the dealer, just as one would need to recalibrate the speedo for a wheel/tire size change?

[gnolivos]

Originally Posted by JABCAT

So whether or not owners accept this (stupid, imo) quirk as being normal, I'm assuming it should be able to be corrected by the dealer, just as one would need to recalibrate the speedo for a wheel/tire size change?

I personally hate this, but it is considered a safety feature believe it or not. On the old F 30 platform, there was a way to adjust this perfectly using BimmerCode, but for now, those specific expert mode menus are not made available to the G 20 platform, so there is no known way to adjust this, except maybe through esys , but even then I have never heard of this being done yet.

[JABCAT]

Originally Posted by gnolivos

I personally hate this, but it is considered a safety feature believe it or not.

If it is a safety feature, it seems more vehicles would be configured this way. In no other vehicle I've owned (36 to-date) has the speedo been off. Curious, if I were to change from the OEM 19" wheels to say 20" wheels, we're saying there is currently no way to calibrate the speedo to account for this?

[gnolivos]

Originally Posted by JABCAT

If it is a safety feature, it seems more vehicles would be configured this way. In no other vehicle I've owned (36 to-date) has the speedo been off. Curious, if I were to change from the OEM 19" wheels to say 20" wheels, we're saying there is currently no way to calibrate the speedo to account for this?

I should have said it's a regulation issue. European regulators require speed to be working a tight margin of error. BMW plays it stupid safe. I hate it.

[j luke]

Originally Posted by JABCAT

So whether or not owners accept this (stupid, imo) quirk as being normal, I'm assuming it should be able to be corrected by the dealer, just as one would need to recalibrate the speedo for a wheel/tire size change?

I don't know about the recalibration for tire changes. As mentioned earlier in the thread its due to regulations that speedometers display within a tight % of actual speed but in no circumstance should they display below actual speed. Its just the margin of error built in. I personally also hate this as I want to see exactly how fast I'm going and make my own decisions as far as whether I will exceed the speed limit and by how much.

[gnolivos]

I posted the bimmercode changes required to adjust it (earlier in this thread). However they applied to F30 and prior. In G20 the entries are not present. I don't know if this is because bimmercode is not exposing them (in expert mode even) or if they simply are no longer available.

[HighlandPete]

Originally Posted by JABCAT

So whether or not owners accept this (stupid, imo) quirk as being normal, I'm assuming it should be able to be corrected by the dealer, just as one would need to recalibrate the speedo for a wheel/tire size change?

As said it is a European regulation, has been for years, so all cars from this side of the pond will be showing a positive figure (by law) at all speeds.

Why change for wheel size? Tires are running similar rolling radius for all OE sizes. No need to recalibrate, comes within tolerance for speedo calibration from factory.

BTW, an exact calibration is only accurate at the tread depth when calibrated, (along with a specific pressure), changes with wear anyway. So no speedo can be 100% accurate through a tire's life cycle. Always some sort of tolerance applying.

[JABCAT]

Originally Posted by HighlandPete

As said it is a European regulation, has been for years, so all cars from this side of the pond will be showing a positive figure (by law) at all speeds.

Why change for wheel size? Tires are running similar rolling radius for all OE sizes. No need to recalibrate, comes within tolerance for speedo calibration from factory.

Interesting considering the vehicle is made in Mexico - not in Europe, and wouldn't be subject to European regulations as it's a U.S.-spec. Not arguing that's the case, seems lazy on BMW's part.

Re:recalibrating for wheel/tire change, if deviating from the OEM sizes/widths the speedometer could be off. Been modifying cars for 30 years, and this has always been the case, I'm sure the Bimmers are no different.

Regardless, it seems the +3 mph deviation is annoying to a lot of people. I've obviously got much to learn on this particular vehicle's quirks.

[springerdrive]

This thread made me curious, so I compared a GPS speedo to my 2022 M340xi and the GPS MPH was just 1 MPH lower than the car's speedo at various speeds.

[Frank_Zuccarini]

Just a thought.............

If I am running OEM 19" wheels with 225/40 R19 tires, the diameter of that tire is 26.1 inches. If I then keep the wheels, but mount tires that are 225/45 R19, then the new tire diameter is 27.0 inches. The increase in diameter is 0.9", or 3.4% larger. That would mean that if the speedometer was displaying 70 mph, the actual speed would be 72.4 mph.

Two questions, please:

- Would this higher sidewall aspect ratio (45%) allow the wheel to fit the car without physical interference?

- If it does fit, would this tire change fix the indicated vs actual speed discrepancy for those who are experiencing it?

Thanks................. Frank